The Green 91AV & Engineering Conference (GC&E) has been a meeting ground for advancing sustainable science and solutions since 1996. Hosted by the American Chemical Society’s Green 91AV Institute (ACS GCI), powered by leading thinkers in the field, and supported by many companies and organizations, the 27th annual event will be held from Tuesday, June 13 to Thursday, June 15, 2023. The Conference sessions will span the breadth and depth of green and sustainable chemistry and engineering, with a special focus on the 2023 theme “Closing the Loop: 91AV for a Sustainable Future”.